[PATCH] genirq: irq: document what an IRQ is
[deliverable/linux.git] / include / linux / irq.h
CommitLineData
06fcb0c6
IM
1#ifndef _LINUX_IRQ_H
2#define _LINUX_IRQ_H
1da177e4
LT
3
4/*
5 * Please do not include this file in generic code. There is currently
6 * no requirement for any architecture to implement anything held
7 * within this file.
8 *
9 * Thanks. --rmk
10 */
11
23f9b317 12#include <linux/smp.h>
1da177e4 13
06fcb0c6 14#ifndef CONFIG_S390
1da177e4
LT
15
16#include <linux/linkage.h>
17#include <linux/cache.h>
18#include <linux/spinlock.h>
19#include <linux/cpumask.h>
908dcecd 20#include <linux/irqreturn.h>
1da177e4
LT
21
22#include <asm/irq.h>
23#include <asm/ptrace.h>
24
25/*
26 * IRQ line status.
27 */
28#define IRQ_INPROGRESS 1 /* IRQ handler active - do not enter! */
29#define IRQ_DISABLED 2 /* IRQ disabled - do not enter! */
30#define IRQ_PENDING 4 /* IRQ pending - replay on enable */
31#define IRQ_REPLAY 8 /* IRQ has been replayed but not acked yet */
32#define IRQ_AUTODETECT 16 /* IRQ is being autodetected */
33#define IRQ_WAITING 32 /* IRQ not yet seen - for autodetection */
34#define IRQ_LEVEL 64 /* IRQ level triggered */
35#define IRQ_MASKED 128 /* IRQ masked - shouldn't be seen again */
0d7012a9 36#ifdef CONFIG_IRQ_PER_CPU
f26fdd59
KW
37# define IRQ_PER_CPU 256 /* IRQ is per CPU */
38# define CHECK_IRQ_PER_CPU(var) ((var) & IRQ_PER_CPU)
39#else
40# define CHECK_IRQ_PER_CPU(var) 0
41#endif
1da177e4 42
3418d724 43#define IRQ_NOPROBE 512 /* IRQ is not valid for probing */
6550c775 44#define IRQ_NOREQUEST 1024 /* IRQ cannot be requested */
94d39e1f 45#define IRQ_NOAUTOEN 2048 /* IRQ will not be enabled on request irq */
6a6de9ef
TG
46#define IRQ_DELAYED_DISABLE \
47 4096 /* IRQ disable (masking) happens delayed. */
48
49/*
50 * IRQ types, see also include/linux/interrupt.h
51 */
52#define IRQ_TYPE_NONE 0x0000 /* Default, unspecified type */
53#define IRQ_TYPE_EDGE_RISING 0x0001 /* Edge rising type */
54#define IRQ_TYPE_EDGE_FALLING 0x0002 /* Edge falling type */
55#define IRQ_TYPE_EDGE_BOTH (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)
56#define IRQ_TYPE_LEVEL_HIGH 0x0004 /* Level high type */
57#define IRQ_TYPE_LEVEL_LOW 0x0008 /* Level low type */
f210be19 58#define IRQ_TYPE_SENSE_MASK 0x000f /* Mask of the above */
6a6de9ef
TG
59#define IRQ_TYPE_SIMPLE 0x0010 /* Simple type */
60#define IRQ_TYPE_PERCPU 0x0020 /* Per CPU type */
61#define IRQ_TYPE_PROBE 0x0040 /* Probing in progress */
62
63struct proc_dir_entry;
64
8fee5c36 65/**
6a6de9ef 66 * struct irq_chip - hardware interrupt chip descriptor
8fee5c36
IM
67 *
68 * @name: name for /proc/interrupts
69 * @startup: start up the interrupt (defaults to ->enable if NULL)
70 * @shutdown: shut down the interrupt (defaults to ->disable if NULL)
71 * @enable: enable the interrupt (defaults to chip->unmask if NULL)
72 * @disable: disable the interrupt (defaults to chip->mask if NULL)
8fee5c36
IM
73 * @ack: start of a new interrupt
74 * @mask: mask an interrupt source
75 * @mask_ack: ack and mask an interrupt source
76 * @unmask: unmask an interrupt source
8fee5c36
IM
77 * @end: end of interrupt
78 * @set_affinity: set the CPU affinity on SMP machines
79 * @retrigger: resend an IRQ to the CPU
80 * @set_type: set the flow type (IRQ_TYPE_LEVEL/etc.) of an IRQ
81 * @set_wake: enable/disable power-management wake-on of an IRQ
82 *
83 * @release: release function solely used by UML
6a6de9ef 84 * @typename: obsoleted by name, kept as migration helper
1da177e4 85 */
6a6de9ef
TG
86struct irq_chip {
87 const char *name;
71d218b7
IM
88 unsigned int (*startup)(unsigned int irq);
89 void (*shutdown)(unsigned int irq);
90 void (*enable)(unsigned int irq);
91 void (*disable)(unsigned int irq);
6a6de9ef 92
71d218b7 93 void (*ack)(unsigned int irq);
6a6de9ef
TG
94 void (*mask)(unsigned int irq);
95 void (*mask_ack)(unsigned int irq);
96 void (*unmask)(unsigned int irq);
97
71d218b7
IM
98 void (*end)(unsigned int irq);
99 void (*set_affinity)(unsigned int irq, cpumask_t dest);
c0ad90a3 100 int (*retrigger)(unsigned int irq);
6a6de9ef
TG
101 int (*set_type)(unsigned int irq, unsigned int flow_type);
102 int (*set_wake)(unsigned int irq, unsigned int on);
c0ad90a3 103
b77d6adc
PBG
104 /* Currently used only by UML, might disappear one day.*/
105#ifdef CONFIG_IRQ_RELEASE_METHOD
71d218b7 106 void (*release)(unsigned int irq, void *dev_id);
b77d6adc 107#endif
6a6de9ef
TG
108 /*
109 * For compatibility, ->typename is copied into ->name.
110 * Will disappear.
111 */
112 const char *typename;
1da177e4
LT
113};
114
8fee5c36
IM
115/**
116 * struct irq_desc - interrupt descriptor
117 *
6a6de9ef
TG
118 * @handle_irq: highlevel irq-events handler [if NULL, __do_IRQ()]
119 * @chip: low level interrupt hardware access
120 * @handler_data: per-IRQ data for the irq_chip methods
121 * @chip_data: platform-specific per-chip private data for the chip
122 * methods, to allow shared chip implementations
8fee5c36
IM
123 * @action: the irq action chain
124 * @status: status information
125 * @depth: disable-depth, for nested irq_disable() calls
126 * @irq_count: stats field to detect stalled irqs
127 * @irqs_unhandled: stats field for spurious unhandled interrupts
128 * @lock: locking for SMP
129 * @affinity: IRQ affinity on SMP
6a6de9ef 130 * @cpu: cpu index useful for balancing
8fee5c36
IM
131 * @pending_mask: pending rebalanced interrupts
132 * @move_irq: need to re-target IRQ destination
133 * @dir: /proc/irq/ procfs entry
134 * @affinity_entry: /proc/irq/smp_affinity procfs entry on SMP
1da177e4
LT
135 *
136 * Pad this out to 32 bytes for cache and indexing reasons.
137 */
34ffdb72 138struct irq_desc {
6a6de9ef
TG
139 void fastcall (*handle_irq)(unsigned int irq,
140 struct irq_desc *desc,
141 struct pt_regs *regs);
142 struct irq_chip *chip;
143 void *handler_data;
71d218b7
IM
144 void *chip_data;
145 struct irqaction *action; /* IRQ action list */
146 unsigned int status; /* IRQ status */
6a6de9ef 147
71d218b7
IM
148 unsigned int depth; /* nested irq disables */
149 unsigned int irq_count; /* For detecting broken IRQs */
150 unsigned int irqs_unhandled;
151 spinlock_t lock;
a53da52f 152#ifdef CONFIG_SMP
71d218b7 153 cpumask_t affinity;
6a6de9ef 154 unsigned int cpu;
a53da52f 155#endif
06fcb0c6 156#if defined(CONFIG_GENERIC_PENDING_IRQ) || defined(CONFIG_IRQBALANCE)
cd916d31 157 cpumask_t pending_mask;
71d218b7 158 unsigned int move_irq; /* need to re-target IRQ dest */
54d5d424 159#endif
4a733ee1
IM
160#ifdef CONFIG_PROC_FS
161 struct proc_dir_entry *dir;
162#endif
34ffdb72 163} ____cacheline_aligned;
1da177e4 164
34ffdb72 165extern struct irq_desc irq_desc[NR_IRQS];
1da177e4 166
34ffdb72
IM
167/*
168 * Migration helpers for obsolete names, they will go away:
169 */
6a6de9ef
TG
170#define hw_interrupt_type irq_chip
171typedef struct irq_chip hw_irq_controller;
172#define no_irq_type no_irq_chip
34ffdb72
IM
173typedef struct irq_desc irq_desc_t;
174
175/*
176 * Pick up the arch-dependent methods:
177 */
178#include <asm/hw_irq.h>
1da177e4 179
06fcb0c6 180extern int setup_irq(unsigned int irq, struct irqaction *new);
1da177e4
LT
181
182#ifdef CONFIG_GENERIC_HARDIRQS
06fcb0c6 183
54d5d424
AR
184#ifdef CONFIG_SMP
185static inline void set_native_irq_info(int irq, cpumask_t mask)
186{
a53da52f 187 irq_desc[irq].affinity = mask;
54d5d424
AR
188}
189#else
190static inline void set_native_irq_info(int irq, cpumask_t mask)
191{
192}
193#endif
194
195#ifdef CONFIG_SMP
196
06fcb0c6 197#if defined(CONFIG_GENERIC_PENDING_IRQ) || defined(CONFIG_IRQBALANCE)
54d5d424 198
c777ac55
AM
199void set_pending_irq(unsigned int irq, cpumask_t mask);
200void move_native_irq(int irq);
54d5d424
AR
201
202#ifdef CONFIG_PCI_MSI
203/*
204 * Wonder why these are dummies?
205 * For e.g the set_ioapic_affinity_vector() calls the set_ioapic_affinity_irq()
206 * counter part after translating the vector to irq info. We need to perform
207 * this operation on the real irq, when we dont use vector, i.e when
208 * pci_use_vector() is false.
209 */
210static inline void move_irq(int irq)
211{
212}
213
214static inline void set_irq_info(int irq, cpumask_t mask)
215{
216}
217
06fcb0c6 218#else /* CONFIG_PCI_MSI */
54d5d424
AR
219
220static inline void move_irq(int irq)
221{
222 move_native_irq(irq);
223}
224
225static inline void set_irq_info(int irq, cpumask_t mask)
226{
227 set_native_irq_info(irq, mask);
228}
54d5d424 229
06fcb0c6
IM
230#endif /* CONFIG_PCI_MSI */
231
232#else /* CONFIG_GENERIC_PENDING_IRQ || CONFIG_IRQBALANCE */
233
234static inline void move_irq(int irq)
235{
236}
237
238static inline void move_native_irq(int irq)
239{
240}
241
242static inline void set_pending_irq(unsigned int irq, cpumask_t mask)
243{
244}
54d5d424 245
54d5d424
AR
246static inline void set_irq_info(int irq, cpumask_t mask)
247{
248 set_native_irq_info(irq, mask);
249}
250
06fcb0c6 251#endif /* CONFIG_GENERIC_PENDING_IRQ */
54d5d424 252
06fcb0c6 253#else /* CONFIG_SMP */
54d5d424
AR
254
255#define move_irq(x)
256#define move_native_irq(x)
257
06fcb0c6 258#endif /* CONFIG_SMP */
54d5d424 259
1b61b910
ZY
260#ifdef CONFIG_IRQBALANCE
261extern void set_balance_irq_affinity(unsigned int irq, cpumask_t mask);
262#else
263static inline void set_balance_irq_affinity(unsigned int irq, cpumask_t mask)
264{
265}
266#endif
267
71d218b7
IM
268#ifdef CONFIG_AUTO_IRQ_AFFINITY
269extern int select_smp_affinity(unsigned int irq);
270#else
271static inline int select_smp_affinity(unsigned int irq)
272{
273 return 1;
274}
275#endif
276
1da177e4 277extern int no_irq_affinity;
1da177e4 278
6a6de9ef
TG
279/* Handle irq action chains: */
280extern int handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
281 struct irqaction *action);
282
283/*
284 * Built-in IRQ handlers for various IRQ types,
285 * callable via desc->chip->handle_irq()
286 */
287extern void fastcall
288handle_level_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs);
289extern void fastcall
290handle_fastack_irq(unsigned int irq, struct irq_desc *desc,
291 struct pt_regs *regs);
292extern void fastcall
293handle_edge_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs);
294extern void fastcall
295handle_simple_irq(unsigned int irq, struct irq_desc *desc,
296 struct pt_regs *regs);
297extern void fastcall
298handle_percpu_irq(unsigned int irq, struct irq_desc *desc,
299 struct pt_regs *regs);
300extern void fastcall
301handle_bad_irq(unsigned int irq, struct irq_desc *desc, struct pt_regs *regs);
302
303/*
304 * Get a descriptive string for the highlevel handler, for
305 * /proc/interrupts output:
306 */
307extern const char *
308handle_irq_name(void fastcall (*handle)(unsigned int, struct irq_desc *,
309 struct pt_regs *));
310
2e60bbb6 311/*
6a6de9ef
TG
312 * Monolithic do_IRQ implementation.
313 * (is an explicit fastcall, because i386 4KSTACKS calls it from assembly)
2e60bbb6 314 */
1da177e4 315extern fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs);
2e60bbb6 316
dae86204
IM
317/*
318 * Architectures call this to let the generic IRQ layer
319 * handle an interrupt. If the descriptor is attached to an
320 * irqchip-style controller then we call the ->handle_irq() handler,
321 * and it calls __do_IRQ() if it's attached to an irqtype-style controller.
322 */
323static inline void generic_handle_irq(unsigned int irq, struct pt_regs *regs)
324{
325 struct irq_desc *desc = irq_desc + irq;
326
327 if (likely(desc->handle_irq))
328 desc->handle_irq(irq, desc, regs);
329 else
330 __do_IRQ(irq, regs);
331}
332
6a6de9ef 333/* Handling of unhandled and spurious interrupts: */
34ffdb72 334extern void note_interrupt(unsigned int irq, struct irq_desc *desc,
2e60bbb6 335 int action_ret, struct pt_regs *regs);
1da177e4 336
a4633adc
TG
337/* Resending of interrupts :*/
338void check_irq_resend(struct irq_desc *desc, unsigned int irq);
339
6a6de9ef 340/* Initialize /proc/irq/ */
1da177e4 341extern void init_irq_proc(void);
eee45269 342
6a6de9ef
TG
343/* Enable/disable irq debugging output: */
344extern int noirqdebug_setup(char *str);
345
346/* Checks whether the interrupt can be requested by request_irq(): */
347extern int can_request_irq(unsigned int irq, unsigned long irqflags);
348
349/* Dummy irq-chip implementation: */
350extern struct irq_chip no_irq_chip;
351
352extern void
353set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
354 void fastcall (*handle)(unsigned int,
355 struct irq_desc *,
356 struct pt_regs *));
357extern void
358__set_irq_handler(unsigned int irq,
359 void fastcall (*handle)(unsigned int, struct irq_desc *,
360 struct pt_regs *),
361 int is_chained);
1da177e4 362
6a6de9ef
TG
363/*
364 * Set a highlevel flow handler for a given IRQ:
365 */
366static inline void
367set_irq_handler(unsigned int irq,
368 void fastcall (*handle)(unsigned int, struct irq_desc *,
369 struct pt_regs *))
370{
371 __set_irq_handler(irq, handle, 0);
372}
373
374/*
375 * Set a highlevel chained flow handler for a given IRQ.
376 * (a chained handler is automatically enabled and set to
377 * IRQ_NOREQUEST and IRQ_NOPROBE)
378 */
379static inline void
380set_irq_chained_handler(unsigned int irq,
381 void fastcall (*handle)(unsigned int, struct irq_desc *,
382 struct pt_regs *))
383{
384 __set_irq_handler(irq, handle, 1);
385}
386
dd87eb3a
TG
387/* Set/get chip/data for an IRQ: */
388
389extern int set_irq_chip(unsigned int irq, struct irq_chip *chip);
390extern int set_irq_data(unsigned int irq, void *data);
391extern int set_irq_chip_data(unsigned int irq, void *data);
392extern int set_irq_type(unsigned int irq, unsigned int type);
393
394#define get_irq_chip(irq) (irq_desc[irq].chip)
395#define get_irq_chip_data(irq) (irq_desc[irq].chip_data)
396#define get_irq_data(irq) (irq_desc[irq].handler_data)
397
6a6de9ef 398#endif /* CONFIG_GENERIC_HARDIRQS */
1da177e4 399
06fcb0c6 400#endif /* !CONFIG_S390 */
1da177e4 401
06fcb0c6 402#endif /* _LINUX_IRQ_H */
This page took 0.216251 seconds and 5 git commands to generate.